KR20110028712A - Voltage range decision circuit - Google Patents

Abstract

PURPOSE: A voltage range determination circuit is provided to accurately determine the voltage range of a variable input voltage by setting a voltage range history in the interface of a partitioned voltage range. CONSTITUTION: In a voltage range determination circuit, a target voltage generation unit(120) generates a target voltage based on an input voltage. The target voltage generation unit generates a target voltage by scaling down an input voltage. A selection voltage generation unit(140) generates fist to second selection voltage based on a reference voltage. A comparison voltage selection unit(160) selects one of the first to second voltage based on an output signal and generates a comparison voltage. An output signal generation unit(180) compares the target voltage and the comparison voltage to generate an output signal.

Description

Voltage range determination circuit {VOLTAGE RANGE DECISION CIRCUIT}

The present invention relates to an electronic device, and more particularly, to a voltage range determination circuit used in a display device of an electronic device.

Recently, as electronic devices become smaller and lower in power, a separate low drop out (LDO) voltage regulator is not used in a display device. That is, when the power supply voltage output from the battery is applied to the display device, the power supply voltage is directly supplied to the display device without passing through the LDO voltage regulator.

In general, since the power supply voltage output from the battery is lowered as the electronic device operates and the voltage level is increased as the battery is charged, the display device of the electronic device that does not use the LDO voltage regulator is a power supply output from the battery. The voltage must be directly supplied to generate the display driving voltage based on the voltage range of the variable power supply voltage.

Accordingly, the conventional display apparatus adopts a method of determining where the variable power supply voltage exists in the partitioned voltage range in determining the voltage range of the variable power supply voltage. However, the conventional display device has a problem in that when the external noise is introduced, the voltage range of the power supply voltage is incorrectly determined at the boundary of the divided voltage range.

One object of the present invention is to provide a voltage range determination circuit capable of accurately determining the voltage range of a variable input voltage even when external noise is introduced.

Another object of the present invention is to provide a voltage supply circuit including the voltage range determination circuit.

Still another object of the present invention is to provide a display driving voltage generating circuit including the voltage supply circuit.

In order to achieve the object of the present invention, the voltage range determination circuit according to an embodiment of the present invention is a target voltage generator for generating a target voltage based on the input voltage, the first to second selection voltage based on the reference voltage A selection voltage generation unit configured to generate a voltage, a comparison voltage selection unit configured to select one of the first to second selection voltages based on an output signal, and output the selected voltage as a comparison voltage, and compare the target voltage with the comparison voltage to output the output signal; It may include an output signal generator for generating.

According to embodiments of the voltage range determination circuit, the target voltage generator may divide the input voltage to generate the target voltage with the input voltage scaled down.

In example embodiments, the voltage range of the input voltage may correspond to a voltage range scaled up with respect to the voltage range of the target voltage.

According to embodiments of the voltage range determination circuit, the selection voltage generation unit may divide the reference voltage to generate the first to second selection voltages.

In example embodiments, the voltage range hysteresis period may correspond to a voltage difference between the first select voltage and the second select voltage.

According to embodiments of the voltage range determination circuit, the comparison voltage selector may output the first selection voltage in response to the output signal in a first logic state and the second voltage in response to the output signal in a second logic state. 2 may be a multiplexer for outputting a selection voltage.

According to embodiments of the voltage range determination circuit, the output signal generator generates the output signal in the first logic state when the target voltage is greater than the comparison voltage, and when the target voltage is less than the comparison voltage. It may be a comparator for generating the output signal of the second logic state.

According to embodiments of the voltage range determination circuit, when the output signal of the first logic state is generated, the target voltage may be determined to exist in a first voltage range, and the output signal of the second logic state may be Once generated, the target voltage may be determined to exist in a second voltage range.

According to embodiments of the voltage range determination circuit, when the target voltage is smaller than the comparison voltage as the input voltage falls, the first voltage range may be narrowed by a voltage range hysteresis interval, and the second voltage The range may be as wide as the voltage range hysteresis interval.

According to embodiments of the voltage range determination circuit, when the target voltage is greater than the comparison voltage as the input voltage is increased, the first voltage range may be widened by a voltage range hysteresis interval, and the second voltage range May be narrowed by the voltage range history period.

In order to achieve the object of the present invention, the voltage range determination circuit according to another embodiment of the present invention is a target voltage generator for generating a target voltage scaled down the input voltage by the voltage distribution of the input voltage, the reference voltage A selection voltage generation unit configured to divide and generate first to nth (where n is an integer of 2 or more) selection voltages composed of a plurality of selection voltages, based on the first to nth output signals; A comparison voltage selection unit configured to select one selection voltage in the selection voltage group and output the first to nth comparison voltages, and compare the target voltages with the first to nth comparison voltages to output the first to nth output voltages; It may include an output signal generator for generating a signal.

In example embodiments, the voltage range of the target voltage may be determined based on a combination of logic states of the first to nth output signals.

According to embodiments of the voltage range determination circuit, the voltage range of the input voltage may correspond to a voltage range scaled up with respect to the voltage range of the target voltage.

According to embodiments of the voltage range determination circuit, first to nth voltage range history periods may respectively correspond to voltage differences of the plurality of selection voltages constituting the first to nth selection voltage groups.

In order to achieve another object of the present invention, the voltage supply circuit according to an embodiment of the present invention is a target voltage generator for generating a target voltage by voltage-dividing the power supply voltage, the first to second selection by voltage-dividing the reference voltage A selection voltage generator configured to generate a voltage; a comparison voltage selector configured to select one of the first to second selection voltages based on an output signal and output the comparison voltage; and to compare the target voltage and the comparison voltage to the output voltage; An output signal generation unit for generating a signal, a decoding unit for decoding a logic state of the output signal to generate a voltage gain control signal, and changing a voltage gain based on the voltage gain control signal, and amplifying an internal voltage using the voltage gain It may include an amplifier for generating an output voltage.

In order to achieve another object of the present invention, a voltage supply circuit according to another embodiment of the present invention is a target voltage generator for generating a target voltage by voltage-dividing a power supply voltage, a plurality of selected voltages by voltage-dividing a reference voltage A selection voltage generation unit configured to generate configured first to nth (where n is an integer of 2 or more), one each within the first to nth selection voltage groups based on the first to nth output signals; A comparison voltage selector which selects a selection voltage and outputs the first to nth comparison voltages, and an output signal generator which generates the first to nth output signals by comparing the target voltage with the first to nth comparison voltages; A decoder configured to decode a logical state combination of the first to nth output signals to generate a voltage gain control signal, and a voltage gain based on the voltage gain control signal. It may include changes, the amplification for amplifying the internal voltage to the voltage gain generating an output voltage parts.

In order to achieve the another object of the present invention, the display driving voltage generation circuit according to an embodiment of the present invention is a target voltage generator for generating a target voltage by voltage distribution of the power supply voltage, voltage division of the reference voltage to the first to A selection voltage generation unit configured to generate a second selection voltage, a comparison voltage selection unit selecting one of the first to second selection voltages based on an output signal, and outputting the selected voltage as a comparison voltage, and comparing the target voltage with the comparison voltage An output signal generator that generates the output signal, a decoder that decodes a logic state of the output signal to generate a voltage gain control signal, and changes a voltage gain based on the voltage gain control signal, and uses an internal voltage as the voltage gain Amplifying unit to generate an output voltage by amplifying a and a display driving voltage based on the output voltage. Castle direct current which can include a DC converting units.

In example embodiments, the display driving voltage generation circuit may include a gate-on voltage, a gate-off voltage, a source driving voltage, and a common voltage.

In order to achieve another object of the present invention, the display driving voltage generation circuit according to another embodiment of the present invention is a target voltage generator for generating a target voltage by voltage division of the power supply voltage, a plurality of selections by voltage division of the reference voltage A selection voltage generator for generating a first to n-th selection voltage group consisting of voltages, wherein n is an integer greater than or equal to 2, within the first to nth selection voltage groups based on first to n-th output signals A comparison voltage selector which selects one selection voltage and outputs the first to nth comparison voltages, and outputs the first to nth output signals by comparing the target voltage with the first to nth comparison voltages; A signal generator to decode a logic state combination of the first to nth output signals to generate a voltage gain control signal; It may include DC converting units - to change the voltage gain and direct current for generating the display drive voltages on the basis of the amplifier and the output voltage that amplifies the internal voltage to the voltage gain generating an output voltage.

In example embodiments, the display driving voltage generation circuit may include a gate-on voltage, a gate-off voltage, a source driving voltage, and a common voltage.

The voltage range determination circuit according to the embodiments of the present invention externally divides a voltage range with respect to a variable input voltage, for example, a power supply voltage output from a battery, and sets a voltage range hysteresis section at a boundary of the partitioned voltage range. Even when noise is introduced, the voltage range of the variable input voltage can be accurately determined.

The voltage supply circuit according to embodiments of the present invention may include the voltage range determination circuit to supply an output voltage close to a constant voltage based on a variable input voltage, for example, a power supply voltage output from a battery. .

The display driving voltage generation circuit according to the embodiments of the present invention includes the voltage supply circuit to stably display the display driving voltage even when a variable input voltage, for example, a power supply voltage output from a battery is directly supplied to the display device. Can be generated.

With respect to the embodiments of the present invention disclosed in the text, specific structural to functional descriptions are merely illustrated for the purpose of describing embodiments of the present invention, embodiments of the present invention may be implemented in various forms and It should not be construed as limited to the embodiments described in.

As the inventive concept allows for various changes and numerous modifications, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms may be used for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between. Other expressions describing the relationship between components, such as "between" and "immediately between," or "neighboring to," and "directly neighboring to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof that is described, and that one or more other features or numbers are present. It should be understood that it does not exclude in advance the possibility of the presence or addition of steps, actions, components, parts or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the dictionary generally used should be construed as meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. The same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

1 is a block diagram illustrating a voltage range determination circuit according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the voltage range determination circuit 100 may include a target voltage generator 120, a selection voltage generator 140, a comparison voltage selector 160, and an output signal generator 180. .

The target voltage generator 120 generates the target voltage Vobj based on the input voltage Vin. In an exemplary embodiment, the target voltage generator 120 may divide the input voltage Vin by using the resistance elements IR1 and IR2 to generate the target voltage Vobj from which the input voltage Vin is scaled down. Can be. In general, since the input voltage Vin input to the electronic device, for example, the power supply voltage output from the battery has a higher voltage level than the voltage scale available inside the electronic device, the input voltage Vin may be changed to the electronic device. To use internally, the input voltage Vin must be scaled down to a voltage scale available inside the electronic device. Accordingly, the target voltage generator 120 may generate the target voltage Vobj of a voltage scale usable inside the electronic device by scaling down the input voltage Vin. However, when the input voltage Vin is a voltage scale usable inside the electronic device, the target voltage Vobj may be substantially the same as the input voltage Vin. The resistors IR1 and IR2 used by the target voltage generator 120 to divide the input voltage Vin may be variable resistance devices. In some embodiments, the target voltage generator 120 may divide the input voltage Vin using an active element such as a diode instead of the resistors IR1 and IR2.

The selection voltage generator 140 generates the first to second selection voltages Vs1 and Vs2 based on the reference voltage Vref. In an embodiment, the selection voltage generator 140 may generate the first to second selection voltages Vs1 and Vs2 by voltage-dividing the reference voltage Vref by using the resistor elements RR1, RR2, and Rr1. Can be. As such, the selection voltage generator 140 may generate the first to second selection voltages Vs1 and Vs2 as candidates of the comparison voltage Vcom, and the first selection voltage Vs1 and the second may be generated. The voltage difference between the selection voltages Vs2 may correspond to a voltage range history period set at the boundary of the partitioned voltage range. That is, the selection voltage generator 140 may determine the voltage range history section by adjusting the voltage difference between the first selection voltage Vs1 and the second selection voltage Vs2. The resistance elements RR1, RR2, and Rr1 used by the selection voltage generator 140 to divide the reference voltage Vref to generate the first to second selection voltages Vs1 and Vs2 may be variable resistance elements. The voltage range hysteresis interval may be determined by varying the resistance value of the resistor Rr1. In some embodiments, the selection voltage generator 140 may divide the reference voltage Vref by using an active element such as a diode instead of the resistor elements RR1, RR2, and Rr1.

The comparison voltage selector 160 receives the first to second selection voltages Vs1 and Vs2 input from the selection voltage generator 140 based on the output signal OUT fed back from the output signal generator 180. Select one of) and output it as the comparison voltage (Vcom). In one embodiment, the comparison voltage selector 160 outputs the first selection voltage Vs1 in response to the output signal OUT of the first logic state, and in response to the output signal OUT of the second logic state. The multiplexer MUX outputting the second selection voltage Vs2 may be implemented. For example, the comparison voltage selector 160 may select a first selection voltage Vs1 having a low voltage level in response to an output signal OUT having a logic high state, and may select a logic low state. In response to the output signal OUT, the second selection voltage Vs2 having a high voltage level may be selected. According to an embodiment, when the selection voltage generator 140 generates a plurality of selection voltages, the comparison voltage selecting unit 160 selects one of the plurality of selection voltages in response to the voltage range of the output signal OUT. It may be implemented in a configuration.

The output signal generator 180 generates an output signal OUT corresponding to the comparison result by comparing the target voltage Vobj with the comparison voltage Vcom. In one embodiment, the output signal generator 180 generates the output signal OUT of the first logic state when the target voltage Vobj is greater than the comparison voltage Vcom, and the target voltage Vobj is the comparison voltage. If smaller than Vcom, the comparator COM may generate an output signal OUT of the second logic state. The voltage range of the target voltage Vobj may be determined based on the output signal OUT generated by the output signal generator 180. When the output signal OUT of the first logic state is generated, the target voltage V It may be determined that Vobj exists in the first voltage range, and when the output signal OUT of the second logic state is generated, it may be determined that the target voltage Vobj exists in the second voltage range. For example, the output signal generator 180 generates the output signal OUT in a logic high state when the target voltage Vobj is greater than the comparison voltage Vcom, thereby causing the target voltage Vobj to exist in a high voltage range. If the target voltage Vobj is less than the comparison voltage Vcom, the output signal OUT of the logic low state may be generated to indicate that the target voltage Vobj exists in the low voltage range. have. Furthermore, since the target voltage Vobj is generated by scaling down the input voltage Vin, the voltage range of the input voltage Vin can be determined by scaling up the voltage range of the target voltage Vobj.

As described above, the voltage range determination circuit 100 partitions the voltage range with respect to the input voltage Vin, for example, the power supply voltage output from the battery, and sets the voltage range history section at the boundary of the divided voltage range. Even when noise is introduced, the voltage range of the input voltage Vin can be accurately determined. Specifically, when the input voltage Vin falls as the electronic device operates, the voltage range determination circuit 100 may compare the target voltage Vobj with the comparison voltage Vcom selected as the first selection voltage Vs1. When it becomes small, the comparison voltage Vcom can be changed to the second selection voltage Vs2 having a voltage level higher than the first selection voltage Vs1. In addition, when the input voltage Vin rises as the battery is charged, the voltage range determination circuit 100 becomes larger than the comparison voltage Vcom that has been selected as the second selection voltage Vs2. The comparison voltage Vcom may be changed to the first selection voltage Vs1 having a voltage level lower than the second selection voltage Vs2. By the operation of the voltage range determination circuit 100, the voltage range of the target voltage Vobj may be accurately determined even if external noise is introduced and a change occurs in the target voltage Vobj, and the voltage of the input voltage Vin The range can also be accurately determined by scaling up the voltage range of the target voltage Vobj.

FIG. 2 is a flowchart illustrating an operation of the voltage range determination circuit of FIG. 1 when the input voltage drops.

Referring to FIG. 2, the voltage range determination circuit 100 may include a target when the target voltage Vobj generated by scaling down the input voltage Vin is greater than the comparison voltage Vcom selected as the first selection voltage Vs1. The voltage Vobj is determined as the first voltage range (S100). The voltage range determination circuit 100 continuously maintains the comparison voltage Vcom as the first selection voltage Vs1 until the target voltage Vobj becomes smaller than the comparison voltage Vcom selected as the first selection voltage Vs1. S110). The voltage range determination circuit 100 determines whether the target voltage Vobj is smaller than the comparison voltage Vcom selected as the first selection voltage Vs1 (S120), so that the target voltage Vobj is the first selection voltage ( When the comparison voltage Vcom becomes smaller than Vs1, the comparison voltage Vcom is changed to the second selection voltage Vs2 having a voltage level higher than the first selection voltage Vs1 (S130). The voltage range determination circuit 100 may reduce the target voltage Vobj to the second voltage range even when external noise is introduced since the target voltage Vobj becomes smaller than the comparison voltage Vcom changed to the second selection voltage Vs2. The determination is made (S140). As such, the voltage range determination circuit 100 determines the first voltage range to be larger than the first selection voltage Vs1 when the input voltage Vin falls, and then selects the first voltage Vobj. At the time when the voltage Vs1 becomes smaller, the first voltage range is changed to a range larger than the second selection voltage Vs2. Also, when the input voltage Vin falls, the voltage range determination circuit 100 determines the second voltage range to be smaller than the first selection voltage Vs1, and the target voltage Vobj is determined by the first selection voltage ( At a time point smaller than Vs1), the second voltage range is changed to a range smaller than the second selection voltage Vs2. That is, when the input voltage Vin falls, the voltage range determination circuit 100 narrows the first voltage range by the voltage range history period when the target voltage Vobj becomes smaller than the first selection voltage Vs1. By extending the second voltage range by the voltage range history period, the voltage range of the target voltage Vobj may be accurately determined even when external noise is introduced. Furthermore, since the voltage range of the input voltage Vin is determined by scaling up the voltage range of the target voltage Vobj, the voltage range determination circuit 100 can also accurately determine the voltage range of the input voltage Vin. have.

3 is a graph illustrating a voltage range changed by the voltage range determination circuit of FIG. 1 when the input voltage drops.

Referring to FIG. 3, when the target voltage Vobj generated by scaling down the input voltage Vin is greater than the comparison voltage Vcom selected as the first selection voltage Vs1, that is, the target voltage Vobj is the first voltage. In the case of having a voltage level A, the first voltage range is determined in the range from the first selection voltage Vs1 to the maximum voltage Vf, and the second voltage range is the first selection in the minimum voltage Vl. It is determined in the range up to the voltage Vs1. That is, even when external noise is introduced, the target voltage Vobj is determined to be the first voltage range until the target voltage Vobj becomes smaller than the first selection voltage Vs1 at the first time point t1. Subsequently, when the target voltage Vobj becomes smaller than the first selection voltage Vs1 at the first time point t1, that is, when the target voltage Vobj has the second voltage level A ', the first voltage range is determined. Is changed in the range from the second selection voltage Vs2 to the maximum voltage Vf, and the second voltage range is changed in the range from the minimum voltage Vl to the second selection voltage Vs2. That is, even when external noise is introduced, the target voltage Vobj is determined as the second voltage range after the target voltage Vobj becomes smaller than the first selection voltage Vs1 at the first time point t1.

In general, when external noise flows in, a change occurs in the input voltage Vin, and therefore, a change occurs in the target voltage Vobj generated by scaling down the input voltage Vin. Accordingly, although the target voltage Vobj having the first voltage level A should be determined as the first voltage range, it may be determined as the second voltage range due to the influence of external noise, and the second voltage level A ' Although the target voltage (Vobj) having a) should be determined as the second voltage range, it may be determined as the first voltage range under the influence of external noise. Therefore, the voltage range determination circuit 100 sets the voltage range history section VRHP at the boundary of the divided voltage range, so that even if external noise flows in and causes a change in the target voltage Vobj, the first voltage level A may occur. And the target voltage Vobj having the second voltage range is determined to be the first voltage range, and the target voltage Vobj having the second voltage level A 'is determined to be the second voltage range. In this case, the voltage range history period VRHP may be determined by the user changing the voltage difference between the first selection voltage Vs1 and the second selection voltage Vs2. In addition, the voltage range of the input voltage Vin may be determined by scaling up the voltage range of the target voltage Vobj.

4 is a flowchart illustrating an operation of the voltage range determination circuit of FIG. 1 when the input voltage is increased.

Referring to FIG. 4, the voltage range determination circuit 100 may determine a target voltage when the target voltage Vobj generated by scaling down the input voltage Vin is smaller than the comparison voltage Vcom selected as the second selection voltage Vs2. The voltage Vobj is determined as the second voltage range (S150). The voltage range determination circuit 100 continuously maintains the comparison voltage Vcom as the second selection voltage Vs2 until the target voltage Vobj becomes greater than the comparison voltage Vcom selected as the second selection voltage Vs2 (S160). )do. The voltage range determination circuit 100 determines whether the target voltage Vobj is greater than the comparison voltage Vcom selected as the second selection voltage Vs2 (S170), so that the target voltage Vobj is the second selection voltage ( When the comparison voltage Vcom is greater than Vs2, the comparison voltage Vcom is changed to the first selection voltage Vs1 having a voltage level lower than the second selection voltage Vs2 (S180). The voltage range determination circuit 100 increases the target voltage Vobj to the first voltage range even when external noise is introduced since the target voltage Vobj becomes larger than the comparison voltage Vcom changed to the first selection voltage Vs1. The determination is made (S190). As described above, when the input voltage Vin increases, the voltage range determination circuit 100 determines the second voltage range to be smaller than the second selection voltage Vs2, and the target voltage Vobj is the second selection voltage. At the point of time greater than Vs2, the second voltage range is changed to a range smaller than the first selection voltage Vs1. In addition, when the input voltage Vin increases, the voltage range determination circuit 100 determines the first voltage range to be larger than the second selection voltage Vs2, and the target voltage Vobj is determined as the second selection voltage ( At the point of time greater than Vs2), the first voltage range is changed to a range larger than the first selection voltage Vs1. That is, when the input voltage Vin rises, the voltage range determination circuit 100 widens the first voltage range by the voltage range history period when the target voltage Vobj becomes larger than the second selection voltage Vs2. By narrowing the two voltage ranges by the voltage range history periods, it is possible to accurately determine the voltage range of the target voltage Vobj even when external noise is introduced. Furthermore, since the voltage range of the input voltage Vin is determined by scaling up the voltage range of the target voltage Vobj, the voltage range determination circuit 100 can also accurately determine the voltage range of the input voltage Vin. have.

5 is a graph illustrating a voltage range changed by the voltage range determination circuit of FIG. 1 when an input voltage rises.

Referring to FIG. 5, when the target voltage Vobj generated by scaling down the input voltage Vin is smaller than the comparison voltage Vcom selected as the second selection voltage Vs2, that is, the target voltage Vobj is the first voltage. In the case of having a voltage level B, the first voltage range is determined from the second selection voltage Vs2 to the maximum voltage Vf, and the second voltage range is the minimum voltage Vl to the second selection voltage. It is determined in the range up to (Vs2). That is, even when external noise is introduced, the target voltage Vobj is determined to be the second voltage range until the target voltage Vobj becomes larger than the second selection voltage Vs2 at the first time point t1. Then, when the target voltage Vobj is greater than the second selection voltage Vs2 at the first time point t1, that is, when the target voltage Vobj has the second voltage level B ', the first voltage range is The second voltage range is changed from the first selection voltage Vs1 to the maximum voltage Vf, and the second voltage range is changed from the minimum voltage Vl to the first selection voltage Vs1. That is, even when external noise is introduced, the target voltage Vobj is determined as the first voltage range after the target voltage Vobj becomes larger than the second selection voltage Vs2 at the first time point t1.

In general, when external noise flows in, a change occurs in the input voltage Vin, and therefore, a change occurs in the target voltage Vobj generated by scaling down the input voltage Vin. Thus, although the target voltage Vobj having the first voltage level B should be determined as the second voltage range, it may be determined as the first voltage range under the influence of external noise, and the second voltage level B ' Although the target voltage (Vobj) having a) must be determined as the first voltage range, it may be determined as the second voltage range due to the influence of external noise. Therefore, the voltage range determination circuit 100 sets the voltage range history period VRHP at the boundary of the partitioned voltage range, so that even if external noise flows into the target voltage Vobj, the first voltage level B may occur. And the target voltage Vobj having the second voltage range is determined to be the second voltage range, and the target voltage Vobj having the second voltage level B 'is determined to be the first voltage range. In this case, the voltage range history period VRHP may be determined by the user changing the voltage difference between the first selection voltage Vs1 and the second selection voltage Vs2. In addition, the voltage range of the input voltage Vin may be determined by scaling up the voltage range of the target voltage Vobj.

6 is a block diagram illustrating a voltage supply circuit including the voltage range determination circuit of FIG. 1.

Referring to FIG. 6, the voltage supply circuit 200 may include a voltage range determination circuit 100, a decoding unit 220, and an amplifier 240.

The voltage range determination circuit 100 receives a variable input voltage Vin, that is, a power supply voltage VPWR output from a battery, generates a target voltage Vobj, and then corresponds to a voltage range of the target voltage Vobj. Generate the output signal OUT. In one embodiment, the voltage range determination circuit 100 divides the power supply voltage VPWR by voltage division to the target voltage generator 120 and the reference voltage Vref to generate the target voltage Vobj. The comparison voltage Vcom is selected by selecting one of the first to second selection voltages Vs1 and Vs2 based on the selection voltage generator 140 generating the second selection voltages Vs1 and Vs2 and the output signal OUT. The output voltage generator 180 may include a comparison voltage selector 160 outputting the target voltage VOB and an output signal generator 180 generating the output signal OUT by comparing the target voltage Vobj with the comparison voltage Vcom. However, since it has been described above, overlapping description will be omitted.

The decoding unit 220 generates a voltage gain control signal CTL by decoding the logic state of the output signal OUT. According to an embodiment, the decoding unit 220 may generate a voltage gain control signal CTL for lowering the voltage gain when the output signal OUT has the first logic state, and the output signal OUT may generate the first signal. In the case of having two logic states, a voltage gain control signal CTL may be generated to increase the voltage gain. For example, the decoding unit 220 has a logic high state when the voltage range determination circuit 100 has a logic high state when the target voltage Vobj generated due to the power supply voltage VPWR is scaled down. When the output signal OUT is generated, the voltage gain control signal CTL for lowering the voltage gain may be generated by decoding the output signal OUT. In addition, the decoder 220 may output an output signal having a logic low state when the voltage range determination circuit 100 is in a low voltage range when the target voltage Vobj generated by the power supply voltage VPWR is scaled down. Once generated by OUT, it is possible to generate a voltage gain control signal CTL for increasing the voltage gain by decoding it.

The amplifier 240 changes the voltage gain based on the voltage gain control signal CTL output from the decoder 220. In one embodiment, the amplifier 240 changes the voltage gain based on the voltage gain control signal CTL output from the decoder 220 and amplifies the internal voltage with the changed voltage gain to output the output voltage VOUT. Can be generated. In some embodiments, the internal voltage may be a target voltage Vobj. The amplifier 240 may change the voltage gain by changing the resistance value of the variable resistor according to the voltage gain control signal CTL output from the decoder 220. For example, the amplifier 240 may be configured based on the voltage gain control signal CTL for lowering the voltage gain when the target voltage Vobj generated by scaling down the power supply voltage VPWR exists in a high voltage range. The voltage gain may be lowered and the voltage gain may be adjusted based on the voltage gain control signal CTL for increasing the voltage gain when the target voltage Vobj generated by scaling down the power supply voltage VPWR is in the low voltage range. It can increase.

As described above, even when the power supply voltage VPWR is variable, the voltage supply circuit 200 accurately determines a voltage range in which the target voltage Vobj generated by scaling down the power supply voltage VPWR and accurately determines the voltage range. The output voltage VOUT close to a stable voltage may be generated by lowering the voltage gain when the target voltage Vobj is in the high voltage range and increasing the voltage gain in the low voltage range. That is, since the voltage supply circuit 200 may substantially function as a voltage regulator, the voltage supply circuit 200 may be used to supply an output voltage VOUT close to a constant voltage in the display device of the electronic device. However, this is just one example, the voltage supply circuit 200 may be used in various devices inside the electronic device.

FIG. 7 is a block diagram illustrating a display driving voltage generation circuit including the voltage supply circuit of FIG. 6.

Referring to FIG. 7, the display driving voltage generation circuit 300 may include a voltage supply circuit 200 and a DC-DC converter 320.

The voltage supply circuit 200 receives the power supply voltage VPWR and supplies an output voltage VOUT close to a constant voltage even when the power supply voltage VPWR is variable. The voltage supply circuit 200 divides the power supply voltage VPWR by voltage division to generate a target voltage Vobj, and divides the reference voltage Vref by first and second selection voltages Vs1. Selects one of the first to second selection voltages Vs1 and Vs2 based on the output signal OUT and the output voltage OUT to generate the comparison voltage Vcom The unit 160, the output signal generator 180 that generates the output signal OUT by comparing the target voltage Vobj with the comparison voltage Vcom, and decodes a logic state of the output signal OUT to decode the voltage gain control signal. A decoding unit 220 generating a CTL and an amplifier 240 changing the voltage gain based on the voltage gain control signal CTL and amplifying an internal voltage with the changed voltage gain to generate an output voltage VOUT. ) May be included. However, since it has been described above, overlapping description will be omitted.

The DC-DC converter 320 may display a display driving voltage, for example, a gate-on voltage Von, a gate-off voltage Voff, a source, based on the output voltage VOUT generated by the voltage supply circuit 200. The driving voltage Vsd and the common voltage Vcomm are generated. In an embodiment, the DC-DC converter 320 may include a first DC-DC converter 322 that generates a common voltage Vcomm based on the output voltage VOUT, and a gate-based voltage based on the output voltage VOUT. A second DC-DC converter 324 for generating an on voltage Von, a third DC-DC converter 326 for generating a gate-off voltage Voff based on the output voltage VOUT, and an output voltage VOUT. ) May include a fourth DC-DC converter 328 to generate a source driving voltage Vsd. As such, the first to fourth DC-DC converters 322, 324, 326, and 328 in the DC-DC converter 320 may display the display driving voltage, for example, the gate-on voltage Von to drive the display device. ), A gate-off voltage Voff, a source driving voltage Vsd, and a common voltage Vcomm may be generated. In one embodiment, the first to fourth DC-DC converters 322, 324, 326, and 328 are respectively located on the primary side of the transformer and the transformer to convert the DC voltage into AC voltage and the secondary of the transformer. Located at the side may include a rectifier for rectifying the transformed AC voltage to a DC voltage.

In general, since the input DC voltage and the output DC voltage at which the DC-DC converters 322, 324, 326, and 328 in the DC-DC converter 320 can operate are determined, the input DC voltage is out of the predetermined value. In this case, the DC-DC converters 322, 324, 326, and 328 in the DC-DC converter 320 may not operate normally or may be damaged. Accordingly, the voltage supply circuit 200 outputs near the constant voltage to the DC-DC converters 322, 324, 326, and 328 in the DC-DC converter 320 even when the power supply voltage VPWR output from the battery is variable. The voltage VOUT can be supplied. To this end, the voltage supply circuit 200 changes the voltage gain according to the voltage range of the target voltage Vobj generated by scaling down the power supply voltage VPWR, amplifies an internal voltage based on the changed voltage gain, and outputs the output voltage. (VOUT) can be generated. As such, the display driving voltage generation circuit 300 may stably display the display driving voltages, for example, the gate-on voltage Von, the gate-off voltage Voff, even if the power supply voltage VPWR output from the battery is variable. Since the source driving voltage Vsd and the common voltage Vcomm can be generated, high operating reliability can be obtained.

8 is a block diagram illustrating a voltage range determination circuit according to another exemplary embodiment of the present invention.

Referring to FIG. 8, the voltage range determination circuit 400 may include a target voltage generator 420, a selection voltage generator 440, a comparison voltage selector 460, and an output signal generator 480. .

The target voltage generator 420 generates the target voltage Vobj based on the input voltage Vin. In an embodiment, the target voltage generator 420 divides the input voltage Vin by using the resistor elements IR1 and IR2 to generate the target voltage Vobj in which the input voltage Vin is scaled down. can do. In general, since the input voltage Vin input to the electronic device, for example, the power supply voltage output from the battery has a higher voltage level than the voltage scale available inside the electronic device, the input voltage Vin may be changed to the electronic device. To use internally, the input voltage (Vin) must be scaled down to a voltage scale available inside the electronic device. Accordingly, the target voltage generator 420 may scale down the input voltage Vin to generate a target voltage Vobj of a voltage scale usable inside the electronic device. However, when the input voltage Vin is a voltage scale usable inside the electronic device, the target voltage Vobj may be substantially the same as the input voltage Vin. The resistors IR1 and IR2 used by the target voltage generator 420 to divide the input voltage Vin may be variable resistance devices. According to an embodiment, the target voltage generator 420 may divide the input voltage Vin by using an active element such as a diode instead of the resistance elements IR1 and IR2.

The selection voltage generator 440 generates the first selection voltage groups V1s1 and V1s2 to the nth selection voltage groups Vns1 and Vns2 based on the reference voltage Vref. In one embodiment, the selection voltage generation unit 440 voltage divides the reference voltage Vref by using the resistor elements RR1,..., RRm, Rr1,..., Rrn. (V1s1, V1s2) to n-th select voltage groups Vns1 and Vns2 may be generated. As such, the selection voltage generation unit 440 may include the first selection voltage groups V1s1 and V1s2 to the nth selection voltage groups Vns1, which are candidates of the first to nth comparison voltages Vcom1 to Vcomn, respectively. Vns2), wherein the plurality of selection voltages V1s1, Vns1, V1s2, The voltage difference between Vns2) may correspond to the first to nth voltage range history periods set at the boundaries of the partitioned voltage ranges, respectively. That is, the selection voltage generator 440 may include the plurality of selection voltages V1s1, Vns1, and V1s2 included in the first to nth selection voltage groups Vns1 and Vns2, respectively. The first to nth voltage range hysteresis intervals may be determined by adjusting the voltage difference between Vns2). The resistor elements RR1 and... Used by the selection voltage generator 440 to divide the reference voltage Vref to generate the first selection voltage groups V1s1 and V1s2 through the nth selection voltage groups Vns1 and Vns2. .., RRm, Rr1, ..., Rrn may be a variable resistance element, and the hysteresis intervals of the first to nth voltage ranges are respectively changed by varying resistance values of the resistance elements Rr1, ..., Rrn. You can decide. In some embodiments, the selection voltage generator 440 may convert the reference voltage Vref into a voltage by using an active element such as a diode instead of the resistors RR1, RRm, Rr1, Rrn. Can be distributed.

The comparison voltage selector 460 selects a first input from the selection voltage generator 440 based on the first to nth output signals OUT1,..., And OUTn fed back from the output signal generator 480. One of a plurality of selection voltages V1s1, ..., Vns1, V1s2, ..., Vns2 constituting the voltage groups V1s1 and V1s2 through n-th selection voltage groups Vns1 and Vns2 is selected and selected. Outputs the first to nth comparison voltages Vcom1 to Vcomn. In an exemplary embodiment, the comparison voltage selector 460 may each select one of the selected voltages V1s1,... In response to the first to nth output signals OUT1,..., OUTn in the first logic state. Outputs Vns1) and outputs the other one of the selected voltages V1s2, ..., Vns2 in response to the first through nth output signals OUT1, ..., OUTn in the second logic state. The first to n th multiplexers MUX1 to MUXn may be implemented. For example, the first to nth multiplexers MUX1 to MUXn of the comparison voltage selector 460 may be connected to the first to nth output signals OUT1 to OUTn of a logic high state. In response, the select voltages V1s1,..., And Vns1 of the low voltage level may be output, respectively, and are respectively high in response to the first to nth output signals OUT1,..., And OUTn of the logic low state. Select voltages V1s2, ..., Vns2 of the voltage level may be output. According to an embodiment, when a plurality of selection voltages are present in the first selection voltage groups V1s1 and V1s2 to nth selection voltage groups Vns1 and Vns2, the comparison voltage selector 460 may be configured to include the first to nth. In response to the voltage range of the output signals OUT1,..., And OUTn, one of the plurality of selection voltages constituting the first selection voltage group V1s1, V1s2 to the nth selection voltage group Vns1, Vns2 is selected. It may be implemented in a configuration of choice.

The output signal generator 480 compares the target voltage Vobj with the first to nth comparison voltages Vcom1,..., And Vcomn so that the first to nth output signals OUT1, corresponding to each comparison result, are output. ..., OUTn). In an exemplary embodiment, the output signal generator 480 may include the first to nth states of the first logic state when the target voltage Vobj is greater than the first to nth comparison voltages Vcom1 to Vcomn. When the output signals OUT1, ..., OUTn are generated and the target voltage Vobj is smaller than the first through nth comparison voltages Vcom1, ..., Vcomn, the first through second states of the second logic state are respectively. The first to n th comparators COM1 to COMn may generate the n th output signals OUT1 to OUTn. In this case, the voltage range of the target voltage Vobj may be determined based on a combination of logic states of the first to nth output signals OUT1,..., OUTn generated by the output signal generator 480. For example, assuming that the output signal generator 480 outputs the first to second output signals OUT1 and OUT2, the target voltage Vobj is greater than the first to second comparison voltages Vcom1 and Vcom2. In this case, the combination of logic states of the first to second output signals OUT1 and OUT2 becomes '11', and thus, the target voltage Vobj may be determined to exist in a high voltage range. When the target voltage Vobj is less than the first comparison voltage Vcom1 and greater than the second comparison voltage Vcom2, the logical state combination of the first to second output signals OUT1 and OUT2 becomes '01', The voltage Vobj may be determined to exist in the intermediate voltage range. When the target voltage Vobj is smaller than the first to second comparison voltages Vcom1 and Vcom2, the logical state combination of the first to second output signals OUT1 and OUT2 becomes '00', and the target voltage Vobj Can be determined to be in the low voltage range. Furthermore, since the target voltage Vobj is generated by scaling down the input voltage Vin, the voltage range of the input voltage Vin can be determined by scaling up the voltage range of the target voltage Vobj.

As such, the voltage range determination circuit 400 partitions the voltage range with respect to the input voltage Vin, for example, the power supply voltage output from the battery, and the first to nth voltage range history periods on the boundary of the divided voltage range. By setting, it is possible to accurately determine the voltage range of the input voltage Vin even when external noise is introduced. In detail, when the input voltage Vin decreases as the electronic device operates, the voltage range determination circuit 400 may turn the target voltage Vobj into one selection voltages V1s1,..., Vns1. When the first to nth comparison voltages Vcom1 to Vcomn are smaller than the selected first to nth comparison voltages Vcom1 to Vcomn, the first to nth comparison voltages Vcom1 to Vcomn are selected as one selection voltages V1s1 to Vcomn. It is possible to change to other selection voltages V1s2, ..., Vns2 having a voltage level higher than Vns1. In addition, when the input voltage Vin increases as the battery is charged, the voltage range determination circuit 400 may select the target voltage Vobj as one of the other selection voltages V1s2,..., Vns2. When the first to nth comparison voltages Vcom1 to Vcomn are greater than the first to nth comparison voltages Vcom1 to Vcomn, the first to nth comparison voltages Vcom1 to Vcomn are selected from the other selection voltages V1s2 to Vns2. It is possible to change to one selection voltages V1s1,..., Vns1 having a voltage level lower than). By the operation of the voltage range determination circuit 400, the voltage range of the target voltage Vobj can be accurately determined even if external noise is introduced and a change occurs in the target voltage Vobj, and the voltage of the input voltage Vin The range can also be accurately determined by scaling up the voltage range of the target voltage Vobj.

9A to 9B are flowcharts illustrating an operation of the voltage range determination circuit of FIG. 8 when the input voltage drops. In the voltage range determination circuit 400, n is assumed to be 3.

9A to 9B, the voltage range determination circuit 400 may include a first comparison voltage Vcom1 in which a target voltage Vobj generated by scaling down an input voltage Vin is selected as the first selection voltage V1s1. If larger, the target voltage Vobj is determined as the first voltage range (S410). The voltage range determination circuit 400 sets the first comparison voltage Vcom1 to the first selection voltage V1s1 until the target voltage Vobj becomes smaller than the first comparison voltage Vcom1 selected as the first selection voltage V1s1. Continue to be maintained (S415). The voltage range determination circuit 400 determines whether the target voltage Vobj is lower than the first comparison voltage Vcom1 selected as the first selection voltage V1s1 (S420), so that the target voltage Vobj is selected first. When the voltage is lower than the first comparison voltage Vcom1 selected as the voltage V1s1, the first comparison voltage Vcom1 is changed to the second selection voltage V1s2 having a voltage level higher than the first selection voltage V1s1 (S425). . Since the voltage range determination circuit 400 becomes smaller than the first comparison voltage Vcom1 in which the target voltage Vobj is changed to the second selection voltage V1s2, the voltage range determination circuit 400 sets the second target voltage Vobj even when external noise is introduced. It is determined as the voltage range (S430). In addition, the voltage range determination circuit 400 sets the second comparison voltage Vcom2 to the third selection voltage (Vcom2) until the target voltage Vobj becomes smaller than the second comparison voltage Vcom2 selected as the third selection voltage V2s1. V2s1) is maintained (S435). The voltage range determination circuit 400 determines whether or not the target voltage Vobj is smaller than the second comparison voltage Vcom2 selected as the third selection voltage V2s1 (S440), so that the target voltage Vobj is the third selection. When the voltage is lower than the second comparison voltage Vcom2 selected as the voltage V2s1, the second comparison voltage Vcom2 is changed to the fourth selection voltage V2s2 having a voltage level higher than the third selection voltage V2s1 (S445). . Since the voltage range determination circuit 400 becomes smaller than the second comparison voltage Vcom2 where the target voltage Vobj is changed to the fourth selection voltage V2s2, the voltage range determination circuit 400 may set the target voltage Vobj as the third voltage even when external noise is introduced. It is determined as the voltage range (S450). Furthermore, the voltage range determination circuit 400 sets the third comparison voltage Vcom3 to the fifth selection voltage until the target voltage Vobj becomes smaller than the third comparison voltage Vcom3 selected as the fifth selection voltage V3s1. It keeps at (V3s1) (S455). The voltage range determination circuit 400 determines whether or not the target voltage Vobj is smaller than the third comparison voltage Vcom3 selected as the fifth selection voltage V3s1 (S460), so that the target voltage Vobj is selected fifth. When the voltage is lower than the third comparison voltage Vcom3 selected as the voltage V3s1, the third comparison voltage Vcom3 is changed to the sixth selection voltage V3s2 having a voltage level higher than the fifth selection voltage V3s1 (S465). . The voltage range determination circuit 400 may reduce the target voltage Vobj to the fourth voltage even when external noise is introduced since the target voltage Vobj becomes smaller than the third comparison voltage Vcom3 changed to the sixth selected voltage V3s2. It is determined in the voltage range (S470). As such, the voltage range determination circuit 400 sets the first to third voltage range hysteresis intervals at the boundaries of the partitioned voltage range, so that even when external noise is introduced when the input voltage Vin falls, the target voltage is applied. The voltage range of (Vobj) can be determined accurately. Furthermore, since the voltage range of the input voltage Vin is determined by scaling up the voltage range of the target voltage Vobj, the voltage range determination circuit 400 can also accurately determine the voltage range of the input voltage Vin. have.

FIG. 10 is a first graph illustrating an operation of the voltage range determination circuit of FIG. 8 when the input voltage drops. In the voltage range determination circuit 400, n is assumed to be 3.

Referring to FIG. 10, when the target voltage Vobj generated by scaling down the input voltage Vin is greater than the first comparison voltage Vcom1 selected as the first selection voltage V1s1, that is, the target voltage Vobj is In the case of having the first voltage level A, the first voltage range is determined in a range from the first selection voltage V1s1 to the maximum voltage Vf, and the second voltage range is in the third selection voltage V2s1. It is determined in the range up to the first selection voltage V1s1. That is, the target voltage Vobj is determined as the first voltage range until the target voltage Vobj becomes smaller than the first selection voltage V1s1 at the first time point t1. Subsequently, when the target voltage Vobj becomes smaller than the first selection voltage V1s1 at the first time point t1, that is, when the target voltage Vobj has the second voltage level A ′, the first voltage range is determined. Is changed in the range from the second selection voltage V1s2 to the maximum voltage Vf, and the second voltage range is changed in the range from the third selection voltage V2s1 to the second selection voltage V1s2. As described above, even when external noise is introduced, the target voltage Vobj is determined to be the second voltage range after the target voltage Vobj becomes smaller than the first selection voltage V1s1 at the first time point t1. In addition, the voltage range of the input voltage Vin is determined by scaling up the voltage range of the target voltage Vobj.

11 is a second graph illustrating the operation of the voltage range determination circuit of FIG. 8 when the input voltage drops. In the voltage range determination circuit 400, n is assumed to be 3.

Referring to FIG. 11, when the target voltage Vobj generated by scaling down the input voltage Vin is greater than the second comparison voltage Vcom2 selected as the third selection voltage V2s1, that is, the target voltage Vobj is In the case of having the second voltage level A ', the second voltage range is determined in the range from the third selection voltage V2s1 to the second selection voltage V1s2, and the third voltage range is the fifth selection voltage ( It is determined in the range from V3s1) to the third selection voltage V2s1. That is, the target voltage Vobj is determined as the second voltage range until the target voltage Vobj becomes smaller than the third selected voltage V2s1 at the second time point t2. Subsequently, when the target voltage Vobj becomes smaller than the third selection voltage V2s1 at the second time point t2, that is, when the target voltage Vobj has the third voltage level A ″, the second voltage. The range is changed from the fourth selection voltage V2s2 to the second selection voltage V1s2, and the third voltage range is changed from the fifth selection voltage V3s1 to the fourth selection voltage V2s2. . As described above, even when external noise is introduced, the target voltage Vobj is determined to be the third voltage range after the target voltage Vobj becomes smaller than the third selection voltage V2s1 at the second time point t2. In addition, the voltage range of the input voltage Vin is determined by scaling up the voltage range of the target voltage Vobj.

FIG. 12 is a third graph illustrating an operation of the voltage range determination circuit of FIG. 8 when the input voltage drops. In the voltage range determination circuit 400, n is assumed to be 3.

Referring to FIG. 12, when the target voltage Vobj generated by scaling down the input voltage Vin is greater than the third comparison voltage Vcom3 selected as the fifth selection voltage V3s1, that is, the target voltage Vobj is In the case of having the second voltage level A '', the third voltage range is determined in the range from the fifth select voltage V3s1 to the fourth select voltage V2s2, and the fourth voltage range is the minimum voltage Vl. ) To a fifth selection voltage V3s1. That is, the target voltage Vobj is determined as the third voltage range until the target voltage Vobj becomes smaller than the fifth selected voltage V3s1 at the third time point t3. Subsequently, when the target voltage Vobj is smaller than the fifth selection voltage V3s1 at the third time point t3, that is, when the target voltage Vobj has the fourth voltage level A '' ', the third voltage is increased. The voltage range is changed from the sixth selection voltage V3s2 to the fourth selection voltage V2s2, and the fourth voltage range is changed from the minimum voltage Vl to the sixth selection voltage V3s2. . As described above, even when external noise is introduced, the target voltage Vobj is determined as the fourth voltage range after the target voltage Vobj becomes smaller than the fifth selected voltage V3s1 at the third time point t3. In addition, the voltage range of the input voltage Vin is determined by scaling up the voltage range of the target voltage Vobj.

FIG. 13 is a graph illustrating a voltage range changed by the voltage range determination circuit of FIG. 8 when the input voltage drops. In the voltage range determination circuit 400, n is assumed to be 3.

Referring to FIG. 13, FIG. 13 is changed by the voltage range determination circuit 400 when the input voltage Vin falls, for example, when the power supply voltage output from the battery falls as the electronic device operates. Indicates the voltage range. The voltage range determination circuit 400 sets the first voltage range history period VRHP1 at a boundary between the first voltage range and the second voltage range, so that noise may be introduced from outside and change even if a change occurs in the target voltage Vobj. The voltage range of the target voltage Vobj may be accurately determined between the first voltage range and the second voltage range. The voltage range determination circuit 400 sets the second voltage range history period VRHP2 at a boundary between the second voltage range and the third voltage range, so that noise may be introduced from outside and change even if a change occurs in the target voltage Vobj. The voltage range of the target voltage Vobj may be accurately determined between the second voltage range and the third voltage range. The voltage range determination circuit 400 sets the third voltage range history period VRHP3 at a boundary between the third voltage range and the fourth voltage range, so that noise may flow from the outside and change even if the target voltage Vobj changes. The voltage range of the target voltage Vobj may be accurately determined between the third voltage range and the fourth voltage range. As described above, the first voltage range history period VRHP1 may be determined by the user changing the voltage difference between the first selection voltage V1s1 and the second selection voltage V1s2 in consideration of the magnitude of noise introduced from the outside. The second voltage range history period VRHP2 may be determined by the user changing the voltage difference between the third selection voltage V2s1 and the fourth selection voltage V2s2 in consideration of the magnitude of noise introduced from the outside. The third voltage range history period VRHP3 may be determined by the user changing the voltage difference between the fifth selected voltage V3s1 and the sixth selected voltage V3s2 in consideration of the magnitude of noise introduced from the outside.

14A to 14B are flowcharts illustrating an operation of the voltage range determination circuit of FIG. 8 when the input voltage rises. In the voltage range determination circuit 400, n is assumed to be 3.

14A to 14B, the voltage range determination circuit 400 may include a third comparison voltage Vcom3 in which a target voltage Vobj generated by scaling down the input voltage Vin is selected as the sixth selection voltage V3s2. If smaller, the target voltage Vobj is determined as the fourth voltage range (S510). The voltage range determination circuit 400 converts the third comparison voltage Vcom3 to the sixth selection voltage V3s2 until the target voltage Vobj becomes greater than the third comparison voltage Vcom3 selected as the sixth selection voltage V3s2. It continues (S515). The voltage range determination circuit 400 determines whether the target voltage Vobj is greater than the third comparison voltage Vcom3 selected as the sixth selection voltage V3s2 (S520), so that the target voltage Vobj is the sixth selection. When the voltage is greater than the third comparison voltage Vcom3 selected as the voltage V3s2, the third comparison voltage Vcom3 is changed into a fifth selection voltage V3s1 having a voltage level lower than the sixth selection voltage V3s2 (S525). The voltage range determination circuit 400 may increase the target voltage Vobj to the third voltage even when external noise is introduced since the target voltage Vobj becomes greater than the third comparison voltage Vcom3 changed to the fifth selection voltage V3s1. It determines with the range (S530). In addition, the voltage range determination circuit 400 sets the second comparison voltage Vcom2 to the fourth selection voltage V2s2 until the target voltage Vobj becomes greater than the second comparison voltage Vcom2 selected as the fourth selection voltage V2s2. Continue to be maintained (S535). The voltage range determination circuit 400 determines whether the target voltage Vobj is greater than the second comparison voltage Vcom2 selected as the fourth selection voltage V2s2 (S540), so that the target voltage Vobj is the fourth selection. When the voltage is greater than the second comparison voltage Vcom2 selected as the voltage V2s2, the second comparison voltage Vcom2 is changed to the third selection voltage V2s1 having a voltage level lower than the fourth selection voltage V2s2 (S545). The voltage range determination circuit 400 may increase the target voltage Vobj to the second voltage even when external noise is introduced since the target voltage Vobj becomes greater than the second comparison voltage Vcom2 changed to the third selection voltage V2s1. It determines with a range (S550). In addition, the voltage range determination circuit 400 sets the first comparison voltage Vcom1 to the second selection voltage V1s2 until the target voltage Vobj becomes greater than the first comparison voltage Vcom1 selected as the second selection voltage V1s2. Continue to be maintained (S555). The voltage range determination circuit 400 determines whether the target voltage Vobj is greater than the first comparison voltage Vcom1 selected as the second selection voltage V1s2 (S560), so that the target voltage Vobj is selected as the second voltage. When the voltage is greater than the first comparison voltage Vcom1 selected as the voltage V1s2, the first comparison voltage Vcom1 is changed to the first selection voltage V1s1 having a voltage level lower than the second selection voltage V1s2 (S565). The voltage range determination circuit 400 increases the target voltage Vobj even when external noise is introduced since the target voltage Vobj becomes larger than the first comparison voltage Vcom1 changed to the first selection voltage V1s1. It determines with a range (S570). As such, the voltage range determination circuit 400 sets the first to third voltage range hysteresis intervals at the boundaries of the partitioned voltage range, so that when the input voltage Vin rises, even if external noise is introduced, the target voltage ( It is possible to accurately determine the voltage range of Vobj). Furthermore, since the voltage range of the input voltage Vin is determined by scaling up the voltage range of the target voltage Vobj, the voltage range determination circuit 400 can also accurately determine the voltage range of the input voltage Vin. have.

FIG. 15 is a first graph illustrating an operation of the voltage range determination circuit of FIG. 8 when the input voltage rises. In the voltage range determination circuit 400, n is assumed to be 3.

Referring to FIG. 15, when the target voltage Vobj generated by scaling down the input voltage Vin is smaller than the third comparison voltage Vcom3 selected as the sixth selection voltage V3s2, that is, the target voltage Vobj is In the case of having the first voltage level B, the fourth voltage range is determined in the range from the minimum voltage Vl to the sixth selected voltage V3s2, and the third voltage range is in the sixth selected voltage V3s2. It is determined in the range up to the fourth selection voltage V2s2. That is, the target voltage Vobj is determined as the fourth voltage range until the target voltage Vobj becomes greater than the sixth selected voltage V3s2 at the first time point t1. Then, when the target voltage Vobj is greater than the sixth selected voltage V3s2 at the first time point t1, that is, when the target voltage Vobj has the second voltage level B ', the fourth voltage range is The minimum voltage V1 is changed to a range from the fifth select voltage V3s1 to the third voltage range, and the third voltage range is changed to a range from the fifth select voltage V3s1 to the fourth select voltage V2s2. As described above, even when external noise is introduced, the target voltage Vobj is determined to be the third voltage range after the target voltage Vobj becomes larger than the sixth selected voltage V3s2 at the first time point t1. In addition, the voltage range of the input voltage Vin is determined by scaling up the voltage range of the target voltage Vobj.

16 is a second graph illustrating the operation of the voltage range determination circuit of FIG. 8 when the input voltage rises. In the voltage range determination circuit 400, n is assumed to be 3.

Referring to FIG. 16, when the target voltage Vobj generated by scaling down the input voltage Vin is smaller than the second comparison voltage Vcom2 selected as the fourth selection voltage V2s2, that is, the target voltage Vobj is In the case of having the second voltage level B ', the third voltage range is determined in a range from the fifth select voltage V3s1 to the fourth select voltage V2s2, and the second voltage range is determined by the fourth select voltage ( It is determined in the range from V2s2) to the second selection voltage V1s2. That is, the target voltage Vobj is determined as the third voltage range until the target voltage Vobj becomes larger than the fourth selected voltage V2s2 at the second time point t2. Subsequently, when the target voltage Vobj is greater than the fourth selected voltage V2s2 at the second time point t2, that is, when the target voltage Vobj has the third voltage level B ″, the third voltage range is set. Is changed from the fifth select voltage V3s1 to the third select voltage V2s1, and the second voltage range is changed from the third select voltage V2s1 to the second select voltage V1s2. As described above, even when external noise is introduced, the target voltage Vobj is determined to be the second voltage range after the target voltage Vobj becomes larger than the fourth selected voltage V2s2 at the second time point t2. In addition, the voltage range of the input voltage Vin is determined by scaling up the voltage range of the target voltage Vobj.

17 is a third graph illustrating the operation of the voltage range determination circuit of FIG. 8 when the input voltage is increased. In the voltage range determination circuit 400, n is assumed to be 3.

Referring to FIG. 17, when the target voltage Vobj generated by scaling down the input voltage Vin is smaller than the first comparison voltage Vcom1 selected as the second selection voltage V1s2, that is, the target voltage Vobj is In the case of having the third voltage level B '', the second voltage range is determined in the range from the third selection voltage V2s1 to the second selection voltage V1s2, and the first voltage range is the second selection voltage. It is determined in the range from (V1s2) to the maximum voltage (Vf). That is, the target voltage Vobj is determined to be the second voltage range until the target voltage Vobj becomes larger than the second selection voltage V1s2 at the third time point t3. Subsequently, when the target voltage Vobj becomes greater than the second selection voltage V1s2 at the third time point t3, that is, when the target voltage Vobj has the fourth voltage level B '' ', the second voltage. The range is changed from the third selection voltage V2s1 to the first selection voltage V1s1, and the first voltage range is changed from the first selection voltage V1s1 to the maximum voltage Vf. As described above, even when external noise is introduced, the target voltage Vobj is determined as the first voltage range after the target voltage Vobj becomes larger than the first selection voltage V1s1 at the third time point t3. In addition, the voltage range of the input voltage Vin is determined by scaling up the voltage range of the target voltage Vobj.

18 is a graph illustrating a voltage range changed by the voltage range determination circuit of FIG. 8 when the input voltage rises. In the voltage range determination circuit 400, n is assumed to be 3.

Referring to FIG. 18, FIG. 18 illustrates a voltage changed by the voltage range determination circuit 400 when the input voltage Vin increases, for example, when a power supply voltage output from the battery increases as the battery is charged. Indicates a range. The voltage range determination circuit 400 sets the first voltage range history period VRHP1 at a boundary between the first voltage range and the second voltage range, so that noise may be introduced from outside and change even if a change occurs in the target voltage Vobj. The voltage range of the target voltage Vobj may be accurately determined between the first voltage range and the second voltage range. The voltage range determination circuit 400 sets the second voltage range history period VRHP2 at a boundary between the second voltage range and the third voltage range, so that noise may be introduced from outside and change even if a change occurs in the target voltage Vobj. The voltage range of the target voltage Vobj may be accurately determined between the second voltage range and the third voltage range. The voltage range determination circuit 400 sets the third voltage range history period VRHP3 at a boundary between the third voltage range and the fourth voltage range, so that noise may flow from the outside and change even if the target voltage Vobj changes. The voltage range of the target voltage Vobj may be accurately determined between the third voltage range and the fourth voltage range. As described above, the first voltage range history period VRHP1 may be determined by the user changing the voltage difference between the first selection voltage V1s1 and the second selection voltage V1s2 in consideration of the magnitude of noise introduced from the outside. The second voltage range history period VRHP2 may be determined by the user changing the voltage difference between the third selection voltage V2s1 and the fourth selection voltage V2s2 in consideration of the magnitude of noise introduced from the outside. The third voltage range history period VRHP3 may be determined by the user changing the voltage difference between the fifth selected voltage V3s1 and the sixth selected voltage V3s2 in consideration of the magnitude of noise introduced from the outside.

FIG. 19 is a block diagram illustrating a voltage supply circuit including the voltage range determination circuit of FIG. 8.

Referring to FIG. 19, the voltage supply circuit 500 may include a voltage range determination circuit 400, a decoder 520, and an amplifier 540.

The voltage range determination circuit 400 generates a target voltage Vobj by receiving a variable input voltage Vin, that is, a power supply voltage VPWR output from a battery, and then corresponds to a voltage range of the target voltage Vobj. The first to n th output signals OUT1,..., OUTn are generated. In an exemplary embodiment, the voltage range determination circuit 400 divides the input voltage Vin to generate a target voltage Vobj in which the input voltage Vin is scaled down to generate a target voltage Vobj, a reference voltage ( A selection voltage generator 440 for generating the first selection voltage groups V1s1 and V1s2 to the nth selection voltage groups Vns1 and Vns2 by voltage-dividing Vref, and the first to nth output signals OUT1,. ..., And selects one selection voltage in each of the first selection voltage groups V1s1 and V1s2 to the nth selection voltage groups Vns1 and Vns2 based on OUTn, so that the first to nth comparison voltages Vcom1,. , And compares the comparison voltage selector 460 and the target voltage Vobj with the first to nth comparison voltages Vcom1 to Vcomn and outputs the first to nth output signals OUT1, ... may include an output signal generator 480 for generating OUTn). However, since it has been described above, overlapping description will be omitted.

The decoding unit 520 generates a voltage gain control signal CTL by decoding the logical state combinations of the first to nth output signals OUT1,..., OUTn. In one embodiment, the decoding unit 520 corresponds to a voltage gain control signal CTL by matching voltage gains with logic state combinations of the first to nth output signals OUT1,..., And OUTn, respectively. You can output The amplifier 540 changes the voltage gain based on the voltage gain control signal CTL output from the decoder 520. In one embodiment, the amplifier 540 changes the voltage gain based on the voltage gain control signal CTL output from the decoder 520, and amplifies the internal voltage with the changed voltage gain to output the output voltage VOUT. Can be generated. In some embodiments, the internal voltage may be a target voltage Vobj. The amplifier 540 may change the voltage gain by changing the resistance value of the variable resistor according to the voltage gain control signal CTL output from the decoder 520.

As such, even when the power supply voltage VPWR is variable, the voltage supply circuit 500 accurately determines a voltage range in which the target voltage Vobj generated by scaling down the power supply voltage VPWR, and accurately determines the voltage range. The output voltage VOUT close to the constant voltage can be generated by controlling the voltage gain on the basis of the method. That is, since the voltage supply circuit 500 may substantially function as a voltage regulator, the voltage supply circuit 500 may be used to supply an output voltage VOUT close to a constant voltage in a display device of an electronic device. However, this is just one example, the voltage supply circuit 500 may be used in various devices inside the electronic device.

20 is a block diagram illustrating a display driving voltage generation circuit including the voltage supply circuit of FIG. 19.

Referring to FIG. 20, the display driving voltage generation circuit 600 may include a voltage supply circuit 500 and a DC-DC converter 620.

The voltage supply circuit 500 receives the power supply voltage VPWR and supplies an output voltage VOUT close to a constant voltage even when the power supply voltage VPWR is variable. The voltage supply circuit 500 divides the power supply voltage VPWR by voltage division to generate the target voltage Vobj, and divides the reference voltage Vref by the voltage selection circuit group V1s1 and V1s2. ) To the nth selection voltage groups Vns1 and Vns2 based on the selection voltage generator 440 and the first to nth output signals OUT1,..., And OUTn. A comparison voltage selector 460 which selects one selection voltage from V1s2 to nth selection voltage groups Vns1 and Vns2 and outputs the selected voltage to the first to nth comparison voltages Vcom1 to Vcomn, An output signal generator for comparing the target voltage Vobj with the first to nth comparison voltages Vcom1 to Vcomn to generate the first to nth output signals OUT1 to OUTn, respectively. 480, a decoder 520 for generating a voltage gain control signal CTL by decoding a logical state combination of the first to nth output signals OUT1,..., OUTn, and voltage gain control. An amplifier 540 may be configured to change the voltage gain based on the signal CTL and generate an output voltage VOUT by amplifying the internal voltage with the changed voltage gain. However, since it has been described above, overlapping description will be omitted.

The DC-DC converter 620 may display a display driving voltage, for example, a gate-on voltage Von, a gate-off voltage Voff, based on an output voltage VOUT generated by the voltage supply circuit 500. The source driving voltage Vsd and the common voltage Vcomm are generated. In an embodiment, the DC-DC converter 620 may include a first DC-DC converter 622 generating a common voltage Vcomm based on the output voltage VOUT, and a gate-based voltage based on the output voltage VOUT. A second DC-DC converter 624 for generating an on voltage Von, a third DC-DC converter 626 for generating a gate-off voltage Voff based on the output voltage VOUT, and an output voltage VOUT. ) May include a fourth DC-DC converter 628 to generate a source driving voltage Vsd. As described above, in the DC-DC converter 620, the first to fourth DC-DC converters 622, 624, 626, and 628 drive the display driving voltage, for example, the gate-on voltage Von to drive the display device. ), A gate-off voltage Voff, a source driving voltage Vsd, and a common voltage Vcomm may be generated. In one embodiment, the first to fourth DC-DC converters 622, 624, 626, and 628 are respectively located on the primary side of the transformer and the transformer to convert the DC voltage into AC voltage and the secondary of the transformer. Located at the side may include a rectifier for rectifying the transformed AC voltage to a DC voltage.

In general, since the input DC voltage and the output DC voltage at which the DC-DC converters 622, 624, 626, and 628 in the DC-DC converter 620 can operate are determined, the input DC voltage may be out of the predetermined value. In this case, the DC-DC converters 622, 624, 626, and 628 in the DC-DC converter 620 may not operate normally or may be damaged. Therefore, the voltage supply circuit 500 outputs near the constant voltage to the DC-DC converters 622, 624, 626, and 628 in the DC-DC converter 620 even when the power supply voltage VPWR output from the battery is variable. The voltage VOUT can be supplied. To this end, the voltage supply circuit 500 changes the voltage gain according to the voltage range of the target voltage Vobj generated by scaling down the power supply voltage VPWR, and amplifies an internal voltage based on the changed voltage gain to output the voltage. The voltage VOUT may be generated. As such, the display driving voltage generation circuit 600 may stably display the display driving voltage, for example, the gate-on voltage Von, the gate-off voltage Voff, even if the power supply voltage VPWR output from the battery is variable. Since the source driving voltage Vsd and the common voltage Vcomm can be generated, high operating reliability can be obtained.

21 is a block diagram illustrating an example of a display apparatus including a display driving voltage generation circuit according to example embodiments.

Referring to FIG. 21, the display apparatus 700 includes a liquid crystal panel 710, a timing controller 720, a gate driver 730, a source driver 740, a gray voltage generator 750, and a display driving voltage generation circuit 760. ) May be included.

The liquid crystal panel 710 includes a pixel matrix composed of pixels formed at regions defined by intersections of the gate lines GL1,..., GLn and the data lines DL1,..., DLm. The pixel includes a liquid crystal cell Clc for adjusting the light transmittance according to the gray scale voltage GV and a thin film transistor TFT for driving the liquid crystal cell Clc. In one embodiment, the thin film transistor TFT is turned on based on the gate-on voltage Von supplied from the gate lines GL1, ..., GLn to be supplied from the data lines DL1, ..., DLm. The gradation voltage GV can be supplied to the liquid crystal cell Clc. In addition, the thin film transistor TFT is turned off based on the gate-off voltage Voff supplied from the gate lines GL1,..., GLn to maintain the gray voltage GV charged in the liquid crystal cell Clc. Can be. In one embodiment, the liquid crystal cell Clc may be equivalently represented as a capacitor, and may include a common electrode facing the liquid crystal and a pixel electrode connected to the thin film transistor TFT. In addition, the liquid crystal cell Clc may include a storage capacitor (not shown) for maintaining a constant gray voltage GV applied to the pixel electrode of the liquid crystal cell Clc for one frame. The liquid crystal cell Clc may adjust light transmittance by changing an arrangement state of liquid crystals having dielectric anisotropy based on the gray voltage GV charged through the thin film transistor TFT.

The timing controller 720 generates a gate control signal GCS for controlling the gate driver 730 and a data control signal DCS for controlling the source driver 740, respectively, and output them to the gate driver 730 and the source, respectively. Supply to driver 740. In addition, the timing controller 720 generates the image signals R, G, and B and supplies them to the source driver 740. In one embodiment, the gate control signal GCS may include a vertical synchronization start signal, a gate clock signal, an output enable signal, and the like, and the data control signal DCS may include a horizontal synchronization start signal, a load signal, an inversion signal, and the like. And a data clock signal. The gate driver 730 may adjust the gate-on voltage Von and the gate-off voltage Voff output from the display driving voltage generation circuit 760 based on the gate control signal GCS supplied from the timing controller 720. The gate lines GL1, ..., GLn are sequentially supplied. The source driver 740 sequentially receives the image signals R, G, and B from the timing controller 720 based on the data control signal DCS supplied from the timing controller 720. Thereafter, the source driver 740 selects the gray voltage GV corresponding to the image signals R, G, and B from the gray voltage GV from the gray voltage generator 750, and selects the data lines DL1, ..., DLm). In some embodiments, the gate driver 730 and the source driver 740 may be mounted on the liquid crystal panel 710 in the form of a tape carrier package (TCP), or may be mounted on a liquid crystal panel 710 in a chip on glass (COG) manner. Can be directly mounted.

The gray voltage generator 750 may generate gray voltages GV based on the source driving voltage Vsd output from the display driving voltage generation circuit 760. In one embodiment, the gray voltage generator 750 may generate gray voltages having a positive value and gray voltages GV having a negative value with respect to the common voltage Vcomm. Accordingly, in driving the liquid crystal panel 710, the display apparatus 700 may have gray voltages GV having a positive value and gray voltages GV having a negative value such that the arrangement direction of the display is changed every predetermined period. By alternately applying these, deterioration of the liquid crystal panel can be prevented. The display driving voltage generation circuit 760 can stably display the display driving voltages, for example, the gate-on voltage Von, the gate-off voltage Voff, and the source driving voltage even if the power supply voltage VPWR output from the battery is variable. (Vsd) and the common voltage (Vcomm) is generated and supplied. In one embodiment, the display driving voltage generator 760 may include a target voltage generator, a selection voltage generator, a comparison voltage selector, an output signal generator, a decoder, an amplifier, and a DC-DC converter. Since it has been described above, overlapping description will be omitted.

As mentioned above, although the voltage range determination circuit, the voltage supply circuit, the display driving voltage generation circuit, and the display apparatus have been described with reference to the embodiments of the present invention, the above-described structure is merely an example and does not depart from the technical spirit of the present invention. It may be modified and changed by those skilled in the art. In addition, the technical problems and effects of the present invention are not limited to those mentioned above, but may be inferred in various ways without departing from the technical spirit of the present invention.

The present invention can be variously applied to an electronic device that receives a variable input voltage, for example, a power supply voltage output from a battery. For example, the present invention may be applied to a computer, a notebook, a digital camera, a video camcorder, a mobile phone, a smartphone, a PMP, a PDA, an MP3 player, a vehicle navigation, and the like.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art may variously modify and modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. It will be appreciated that it can be changed.

1 is a block diagram illustrating a voltage range determination circuit according to an exemplary embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation of the voltage range determination circuit of FIG. 1 when the input voltage drops.

3 is a graph illustrating a voltage range changed by the voltage range determination circuit of FIG. 1 when the input voltage drops.

4 is a flowchart illustrating an operation of the voltage range determination circuit of FIG. 1 when the input voltage is increased.

5 is a graph illustrating a voltage range changed by the voltage range determination circuit of FIG. 1 when an input voltage rises.

6 is a block diagram illustrating a voltage supply circuit including the voltage range determination circuit of FIG. 1.

FIG. 7 is a block diagram illustrating a display driving voltage generation circuit including the voltage supply circuit of FIG. 6.

8 is a block diagram illustrating a voltage range determination circuit according to another exemplary embodiment of the present invention.

9A to 9B are flowcharts illustrating an operation of the voltage range determination circuit of FIG. 8 when the input voltage drops.

FIG. 10 is a first graph illustrating an operation of the voltage range determination circuit of FIG. 8 when the input voltage drops.

11 is a second graph illustrating the operation of the voltage range determination circuit of FIG. 8 when the input voltage drops.

FIG. 12 is a third graph illustrating an operation of the voltage range determination circuit of FIG. 8 when the input voltage drops.

FIG. 13 is a graph illustrating a voltage range changed by the voltage range determination circuit of FIG. 8 when the input voltage drops.

14A to 14B are flowcharts illustrating an operation of the voltage range determination circuit of FIG. 8 when the input voltage rises.

FIG. 15 is a first graph illustrating an operation of the voltage range determination circuit of FIG. 8 when the input voltage rises.

16 is a second graph illustrating the operation of the voltage range determination circuit of FIG. 8 when the input voltage rises.

17 is a third graph illustrating the operation of the voltage range determination circuit of FIG. 8 when the input voltage is increased.

18 is a graph illustrating a voltage range changed by the voltage range determination circuit of FIG. 8 when the input voltage rises.

FIG. 19 is a block diagram illustrating a voltage supply circuit including the voltage range determination circuit of FIG. 8.

20 is a block diagram illustrating a display driving voltage generation circuit including the voltage supply circuit of FIG. 19.

21 is a block diagram illustrating an example of a display apparatus including a display driving voltage generation circuit according to example embodiments.

<Description of the symbols for the main parts of the drawings>

100, 400: voltage range determination circuit 120, 420: target voltage generator

140 and 440: selection voltage generator 160 and 460: comparison voltage selector

180, 480: output signal generator 200, 500: voltage supply circuit

300, 600: display driving voltage generation circuit

700: display device

Claims (10)

A target voltage generator configured to generate a target voltage based on an input voltage; A selection voltage generator configured to generate first to second selection voltages based on the reference voltage; A comparison voltage selector configured to select one of the first to second selection voltages based on an output signal and output the comparison voltage as a comparison voltage; And And an output signal generator configured to generate the output signal by comparing the target voltage with the comparison voltage. The voltage range determination circuit of claim 1, wherein the target voltage generator divides the input voltage to generate the target voltage with the input voltage scaled down. The voltage range determination circuit of claim 2, wherein the voltage range of the input voltage corresponds to a voltage range scaled up with respect to the voltage range of the target voltage. The voltage range determination circuit of claim 1, wherein the selection voltage generation unit divides the reference voltage to generate the first to second selection voltages. 5. The voltage range determination circuit according to claim 4, wherein a voltage range hysteresis period corresponds to a voltage difference between the first selected voltage and the second selected voltage. The display device of claim 1, wherein the comparison voltage selector outputs the first selection voltage in response to the output signal in a first logic state, and outputs the second selection voltage in response to the output signal in a second logic state. A voltage range determination circuit, characterized in that it is a multiplexer. The method of claim 6, wherein the output signal generator generates the output signal in the first logic state when the target voltage is greater than the comparison voltage, and generates the output signal in the first logic state when the target voltage is less than the comparison voltage. And a comparator for generating the output signal. A target voltage generator configured to divide a voltage of an input voltage to generate a target voltage of which the input voltage is scaled down; A selection voltage generator configured to voltage divide the reference voltage to generate first to nth (where n is an integer of 2 or more) selection voltage groups including a plurality of selection voltages; A comparison voltage selector configured to select one selection voltage from each of the first to nth selection voltage groups based on the first to nth output signals and output the first to nth comparison voltages; And And an output signal generator configured to generate the first to nth output signals by comparing the target voltage with the first to nth comparison voltages. 9. The voltage range determination circuit of claim 8, wherein the voltage range of the target voltage is determined based on a combination of logic states of the first to nth output signals. 10. The voltage range determination circuit of claim 9, wherein the voltage range of the input voltage corresponds to a voltage range scaled up with respect to the voltage range of the target voltage.

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